If there were a Hall of Fame of business catch phrases, BHAG (big hairy audacious goal) would deserve an emerald-encrusted display case all its own.

Since popularized by Jim Collins and Jerry Porras in this article nearly 20 years ago, the phrase (pronounced Bee-Hag) has been uttered at nearly every "big picture" brainstorming session I've ever attended, often with a chuckle or smile, as if the presenters coined it themselves.

The problem with BHAGs, like so many catch phrases, is that people forget the meaning behind the mnemonic device. Because "audacious goals" can be dangerous things without corresponding, and equally essential, "core values."

Without adherence to core values, anything goes.

Volkswagen's BHAG to become the world's No. 1 automaker by 2018 is a likely example. Cheating on emission tests to meet audacious sales goals comes easy when not put in check by values like respect for customers—let alone every living thing on the planet.

Years ago, a clever client of mine foresaw such workplace dilemmas and devised a simple evaluation system to keep his employees on track: a star with the BHAG at the center and the company's five values, one at each point.

Once a quarter, the CEO would rank the company on how it was performing against both its BHAG and core values, assigning each a simple ranking of 1 through 5. So if, for example, the company was exceeding its sales goals, but customer satisfaction fell short, then the business couldn't be considered a "star."

Perhaps if VW had instituted similar checks and balances, it could have prevented the ethical blindness that transformed its BHAG into a BHAM—a big hairy audacious mess.